1/*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#if defined(LIBC_SCCS) && !defined(lint)
34static char sccsid[] = "@(#)findfp.c 8.2 (Berkeley) 1/4/94";
35#endif /* LIBC_SCCS and not lint */
36#include <sys/cdefs.h>
|
37__FBSDID("$FreeBSD: head/lib/libc/stdio/findfp.c 165903 2007-01-09 00:28:16Z imp $");
|
| 37__FBSDID("$FreeBSD: head/lib/libc/stdio/findfp.c 178287 2008-04-17 22:17:54Z jhb $"); |
38
39#include <sys/param.h>
40#include <machine/atomic.h>
41#include <unistd.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45
46#include <spinlock.h>
47
48#include "libc_private.h"
49#include "local.h"
50#include "glue.h"
51
52int __sdidinit;
53
54#define NDYNAMIC 10 /* add ten more whenever necessary */
55
56#define std(flags, file) \
|
57 {0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite, \
58 {0}, __sFX + file}
|
| 57 {0,0,0,flags,file,{0},0,__sF+file,__sclose,__sread,__sseek,__swrite} |
58 /* p r w flags file _bf z cookie close read seek write */
|
60 /* _ub _extra */
|
| 59 |
60 /* the usual - (stdin + stdout + stderr) */
61static FILE usual[FOPEN_MAX - 3];
|
63static struct __sFILEX usual_extra[FOPEN_MAX - 3];
|
62static struct glue uglue = { NULL, FOPEN_MAX - 3, usual };
63
|
66static struct __sFILEX __sFX[3];
67
68/*
69 * We can't make this 'static' until 6.0-current due to binary
70 * compatibility concerns. This also means we cannot change the
71 * sizeof(FILE) until that time either and must continue to use the
72 * __sFILEX stuff to add to FILE.
73 */
74FILE __sF[3] = {
|
| 64static FILE __sF[3] = { |
65 std(__SRD, STDIN_FILENO),
66 std(__SWR, STDOUT_FILENO),
67 std(__SWR|__SNBF, STDERR_FILENO)
68};
69
|
80/*
81 * The following kludge is done to ensure enough binary compatibility
82 * with future versions of libc. Or rather it allows us to work with
83 * libraries that have been built with a newer libc that defines these
84 * symbols and expects libc to provide them. We only have need to support
85 * i386 because it is the only "old" system we have deployed.
86 */
|
70FILE *__stdinp = &__sF[0];
71FILE *__stdoutp = &__sF[1];
72FILE *__stderrp = &__sF[2];
73
74struct glue __sglue = { &uglue, 3, __sF };
75static struct glue *lastglue = &uglue;
76
77static struct glue * moreglue(int);
78
79static spinlock_t thread_lock = _SPINLOCK_INITIALIZER;
80#define THREAD_LOCK() if (__isthreaded) _SPINLOCK(&thread_lock)
81#define THREAD_UNLOCK() if (__isthreaded) _SPINUNLOCK(&thread_lock)
82
83#if NOT_YET
84#define SET_GLUE_PTR(ptr, val) atomic_set_rel_ptr(&(ptr), (uintptr_t)(val))
85#else
86#define SET_GLUE_PTR(ptr, val) ptr = val
87#endif
88
89static struct glue *
90moreglue(n)
91 int n;
92{
93 struct glue *g;
94 static FILE empty;
|
112 static struct __sFILEX emptyx;
|
95 FILE *p;
|
114 struct __sFILEX *fx;
|
96
|
116 g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE) +
117 n * sizeof(struct __sFILEX));
|
| 97 g = (struct glue *)malloc(sizeof(*g) + ALIGNBYTES + n * sizeof(FILE)); |
98 if (g == NULL)
99 return (NULL);
100 p = (FILE *)ALIGN(g + 1);
|
121 fx = (struct __sFILEX *)&p[n];
|
101 g->next = NULL;
102 g->niobs = n;
103 g->iobs = p;
|
125 while (--n >= 0) {
126 *p = empty;
127 p->_extra = fx;
128 *p->_extra = emptyx;
129 p++, fx++;
130 }
|
104 while (--n >= 0)
105 *p++ = empty; |
106 return (g);
107}
108
109/*
110 * Find a free FILE for fopen et al.
111 */
112FILE *
113__sfp()
114{
115 FILE *fp;
116 int n;
117 struct glue *g;
118
119 if (!__sdidinit)
120 __sinit();
121 /*
122 * The list must be locked because a FILE may be updated.
123 */
124 THREAD_LOCK();
125 for (g = &__sglue; g != NULL; g = g->next) {
126 for (fp = g->iobs, n = g->niobs; --n >= 0; fp++)
127 if (fp->_flags == 0)
128 goto found;
129 }
130 THREAD_UNLOCK(); /* don't hold lock while malloc()ing. */
131 if ((g = moreglue(NDYNAMIC)) == NULL)
132 return (NULL);
133 THREAD_LOCK(); /* reacquire the lock */
134 SET_GLUE_PTR(lastglue->next, g); /* atomically append glue to list */
135 lastglue = g; /* not atomic; only accessed when locked */
136 fp = g->iobs;
137found:
138 fp->_flags = 1; /* reserve this slot; caller sets real flags */
139 THREAD_UNLOCK();
140 fp->_p = NULL; /* no current pointer */
141 fp->_w = 0; /* nothing to read or write */
142 fp->_r = 0;
143 fp->_bf._base = NULL; /* no buffer */
144 fp->_bf._size = 0;
145 fp->_lbfsize = 0; /* not line buffered */
146 fp->_file = -1; /* no file */
147/* fp->_cookie = <any>; */ /* caller sets cookie, _read/_write etc */
148 fp->_ub._base = NULL; /* no ungetc buffer */
149 fp->_ub._size = 0;
150 fp->_lb._base = NULL; /* no line buffer */
151 fp->_lb._size = 0;
152/* fp->_lock = NULL; */ /* once set always set (reused) */
|
178 fp->_extra->orientation = 0;
179 memset(&fp->_extra->mbstate, 0, sizeof(mbstate_t));
|
153 fp->_orientation = 0;
154 memset(&fp->_mbstate, 0, sizeof(mbstate_t)); |
155 return (fp);
156}
157
158/*
159 * XXX. Force immediate allocation of internal memory. Not used by stdio,
160 * but documented historically for certain applications. Bad applications.
161 */
162__warn_references(f_prealloc,
163 "warning: this program uses f_prealloc(), which is not recommended.");
164
165void
166f_prealloc()
167{
168 struct glue *g;
169 int n;
170
171 n = getdtablesize() - FOPEN_MAX + 20; /* 20 for slop. */
172 /*
173 * It should be safe to walk the list without locking it;
174 * new nodes are only added to the end and none are ever
175 * removed.
176 */
177 for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next)
178 /* void */;
179 if ((n > 0) && ((g = moreglue(n)) != NULL)) {
180 THREAD_LOCK();
181 SET_GLUE_PTR(lastglue->next, g);
182 lastglue = g;
183 THREAD_UNLOCK();
184 }
185}
186
187/*
188 * exit() calls _cleanup() through *__cleanup, set whenever we
189 * open or buffer a file. This chicanery is done so that programs
190 * that do not use stdio need not link it all in.
191 *
192 * The name `_cleanup' is, alas, fairly well known outside stdio.
193 */
194void
195_cleanup()
196{
197 /* (void) _fwalk(fclose); */
198 (void) _fwalk(__sflush); /* `cheating' */
199}
200
201/*
202 * __sinit() is called whenever stdio's internal variables must be set up.
203 */
204void
205__sinit()
206{
|
232 int i;
|
207
|
234 THREAD_LOCK();
235 if (__sdidinit == 0) {
236 /* Set _extra for the usual suspects. */
237 for (i = 0; i < FOPEN_MAX - 3; i++)
238 usual[i]._extra = &usual_extra[i];
239
240 /* Make sure we clean up on exit. */
241 __cleanup = _cleanup; /* conservative */
242 __sdidinit = 1;
243 }
244 THREAD_UNLOCK();
|
208 /* Make sure we clean up on exit. */
209 __cleanup = _cleanup; /* conservative */
210 __sdidinit = 1; |
211}
|